July 20, 1953
REACTION OF ENOLACETATES WITH N-IODOSUCCINIMIDE [CONTRIBUTION FROM
a-Iodoketones (Part 2)
THE
3493
DEPARTMENT O F CHEMISTRY O F WAYNE UNIVERSITY]
Reaction of Enol Acetates with N-Iodosuccinimide2
BY CARL DJERASSIAND CARL T.LENK3 RECEIVED FEBRUARY 21, 1953 As illustrated in three instances, enol acetates react with N-iodosuccinimide to yield the corresponding a-iodoketone (or aldehyde) and N-acetylsuccinimide. Iodine monochloride can be substituted for N-iodosuccinimide, but the latter reagent has the advantage of not attacking nuclear double bonds. As an illustration of this selective iodination, A6-pregnen-3P-ol-20one was converted in three steps to A6-pregnene-3@-21-diol-20-one diacetate. 0 OAc In contrast to their chloro or bromo analogs, I a-iodoketones (and aldehydes) have been studied CHI( C H ~ ) ~ C I1H ~ C C----+ H S CH,
